A modified high-strength nylon yarn and its preparation process

Abstract

The present invention relates to the field of fiber technology, and discloses a modified high-strength nylon yarn and a preparation process thereof. The modified high-strength nylon yarn comprises 90-98 parts of nylon resin and 2-10 parts of polyamide modifier by weight. The polyamide modifier contains a large number of flexible ether bonds in its molecular chain, which has a good toughening effect on the nylon yarn and is conducive to improving the elongation at break. At the same time, it contains a rigid imide ring structure, which has a reinforcing effect on the nylon yarn and is conducive to improving the breaking strength, thereby enabling the nylon yarn to have a higher breaking strength while maintaining high elongation at break and toughness. The thermal decomposition temperature and heat resistance of the nylon yarn are also improved, and the polyamide modifier has good practical applications in high-strength, high-toughness, high-temperature resistant fibers, textiles, etc.

Description

Technical Field

[0001] The present invention relates to the field of fiber technology, in particular to a modified high-strength nylon yarn and a preparation process thereof. Background Art

[0002] Nylon yarn is a high-performance fiber material, primarily made by spinning nylon resin. It boasts high elasticity, good abrasion resistance, and excellent moisture absorption, making it widely used. However, conventional nylon yarn suffers from poor tensile properties, making it difficult to achieve both high strength and toughness. Currently, the main methods for modifying nylon fibers include blending, copolymerization, and grafting.

[0003] The mechanical properties of nylon fibers can be improved by spinning highly elastic polymers with nylon. Chinese Patent Publication No. CN112127007B discloses a polyurethane-nylon 6 block copolymer, a preparation method thereof, and a polyurethane-nylon 6 elastic fiber. The fibers obtained by melt-spinning the polyurethane-nylon 6 block copolymer have advantages such as high strength and high resilience. However, the fibers lack good heat resistance, which is not conducive to their practical application in high-temperature resistant fibers and textiles. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a modified high-strength nylon yarn and a preparation process thereof, which solves the problem that the mechanical properties of nylon yarn are poor and it is difficult for nylon yarn to have both good strength and toughness, while improving the heat resistance of nylon yarn.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a modified high-strength nylon yarn and a preparation process thereof, wherein the modified high-strength nylon yarn comprises 90-98 parts by weight of nylon resin and 2-10 parts by weight of polyamide modifier; the preparation process of the high-strength nylon yarn is as follows:

[0006] (1) Add glacial acetic acid, trimellitic anhydride, and 2,2'-oxybis(ethylamine) into a flask equipped with a condenser reflux tube, introduce nitrogen, stir to react, cool, filter, and wash with methanol. The product is recrystallized in dichloromethane to obtain an imide carboxyl monomer.

[0007] (2) Add thionyl chloride, N,N-dimethylformamide, and imidocarboxyl monomer into a flask equipped with a condenser reflux tube, stir to react, then distill under reduced pressure and dry to obtain imidocarboxyl chloride monomer.

[0008] (3) Add imidoyl chloride monomer, 2,2'-oxybis(ethylamine) and triethylamine to N,N-dimethylformamide, stir the reaction, and then distill under reduced pressure, wash with water and ethanol, and dry to obtain a polyamide modifier.

[0009] (4) Nylon resin and polyamide modifier are mixed, spun in a melt spinning machine, and then drawn through a hot drawing device to obtain modified high-strength nylon yarn.

[0010] Furthermore, the ratio of trimellitic anhydride to 2,2'-oxybis(ethylamine) in (1) is (2-2.6) mol:1 mol. The CAS registration number of trimellitic anhydride is 552-30-7, and the CAS registration number of 2,2'-oxybis(ethylamine) is 2752-17-2.

[0011] Furthermore, (1) the reaction is carried out at 115-120°C for 12-18 hours.

[0012] Furthermore, the ratio of thionyl chloride, N,N-dimethylformamide, and imide carboxyl monomer in (2) is (1-1.4) L: (0.3-0.6) mL: 1 mol.

[0013] Furthermore, the reaction in (2) is stirred at 60-75°C for 5-8 hours.

[0014] Furthermore, the ratio of the imidoyl chloride monomer, 2,2'-oxybis(ethylamine), and triethylamine in (3) is 1 mol: (1-1.2) mol: (2-2.6) mol.

[0015] Furthermore, the reaction in (3) is stirred at 20-40°C for 12-18 hours.

[0016] Furthermore, the spinning temperature in (4) is 240-260°C.

[0017] Furthermore, the temperature during the stretching in (4) is 100-120°C.

[0018] The present invention adopts the above-mentioned technical solution, achieving the following beneficial technical effects: an imide chloride monomer and 2,2'-oxybis(ethylamine) are polymerized to obtain a polyamide modifier, which is then melt-spun with a nylon resin to obtain a modified high-strength nylon yarn. The polyamide modifier contains a large number of flexible ether bonds in its molecular chain, which has a good toughening effect on the nylon yarn and is beneficial for improving the elongation at break. At the same time, it contains a rigid imide ring structure, which has a reinforcing effect on the nylon yarn and is beneficial for improving the breaking strength. Thus, the nylon yarn maintains high elongation at break and toughness while also having high breaking strength. The polyamide modifier contains an imide ring structure, has strong high-temperature resistance, is not easily thermally decomposed, and significantly improves the thermal decomposition temperature and heat resistance of the nylon yarn, making the nylon yarn have good practical applications in high-strength, high-toughness, high-temperature-resistant fibers and textiles. DETAILED DESCRIPTION

[0019] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0020] The brand of the following nylon resin is M2500I, which is sourced from Ningbo Senhong Plastics Co., Ltd. Example 1

[0021] (1) To a flask equipped with a reflux tube, 180 mL of glacial acetic acid, 60 mmol of trimellitic anhydride, and 30 mmol of 2,2'-oxybis(ethylamine) were added, nitrogen was introduced, and the mixture was heated to 120 °C and stirred for 12 h. After cooling, the mixture was filtered and the product was washed with methanol. The product was then recrystallized from dichloromethane to obtain an imide carboxyl monomer as a light yellow solid with a yield of 7.76 g.

[0022] (2) Add 60 mL of thionyl chloride, 0.02 mL of N,N-dimethylformamide, and 50 mmol of imidocarboxyl monomer to a flask equipped with a condenser reflux tube, heat to 75°C, stir and react for 5 h, distill under reduced pressure, and dry to obtain imidocarboxyl chloride monomer as a light yellow solid with a yield of 19.57 g. The preparation reaction formula is:

[0023] .

[0024] (3) Add 50 mmol of imidoyl chloride monomer, 54 mmol of 2,2'-oxybis(ethylamine), and 110 mmol of triethylamine to 300 mL of N,N-dimethylformamide, stir and react at 25°C for 18 hours, distill under reduced pressure, wash the product with water and ethanol, and dry it to obtain a polyamide modifier. The preparation reaction formula is:

[0025] .

[0026] (4) 9.8 kg of nylon resin and 0.2 kg of polyamide modifier were mixed and spun in a melt spinning machine at a spinning temperature of 260 °C. The mixture was then stretched in a hot stretching device at a stretching temperature of 120 °C and a stretching ratio of 4 to obtain modified high-strength nylon yarn.

[0027] Comparative Example 1: The difference between this comparative example and Example 1 is that no polyamide modifier is added.

[0028] (1) 9.8 kg of nylon resin was spun in a melt spinning machine at a spinning temperature of 260°C, and then stretched in a hot stretching device at a stretching temperature of 120°C and a stretching ratio of 4 to obtain nylon yarn.

[0029] Comparative Example 2: The difference between this comparative example and Example 1 is that 4,4-chloroformylphenyl ether is used instead of imidoyl chloride monomer when preparing the polyamide modifier. The structural formula of 4,4-chloroformylphenyl ether is , CAS registration number is 7158-32-9.

[0030] (1) Add 50 mmol of 4,4-chloroformylphenyl ether, 54 mmol of 2,2'-oxybis(ethylamine), and 110 mmol of triethylamine to 300 mL of N,N-dimethylformamide, stir and react at 25°C for 18 h, distill under reduced pressure, wash the product with water and ethanol, and dry it to obtain a polyamide modifier.

[0031] (2) 9.8 kg of nylon resin and 0.2 kg of polyamide modifier were mixed and spun in a melt spinning machine at a spinning temperature of 260 °C. The mixture was then stretched in a hot stretching device at a stretching temperature of 120 °C and a stretching ratio of 4 to obtain modified nylon yarn.

[0032] Comparative Example 3: The difference between this comparative example and Example 1 is that ethylenediamine is used instead of 2,2'-oxybis(ethylamine) when preparing the imide carboxyl monomer.

[0033] (1) Add 180 mL of glacial acetic acid, 60 mmol of trimellitic anhydride, and 30 mmol of ethylenediamine to a flask equipped with a condenser reflux tube, introduce nitrogen, heat to 120 ° C, stir and react for 12 hours, cool and filter, wash the product with methanol, and then recrystallize in dichloromethane to obtain an imide carboxyl monomer. The structural formula is .

[0034] (2) Add 60 mL of thionyl chloride, 0.02 mL of N,N-dimethylformamide, and 50 mmol of imidocarboxyl monomer to a flask equipped with a condenser reflux tube, heat to 75 ° C, stir and react for 5 hours, distill under reduced pressure, and dry to obtain imidocarboxyl chloride monomer. The structural formula is .

[0035] (3) Add 50 mmol of imidoyl chloride monomer, 54 mmol of 2,2'-oxybis(ethylamine), and 110 mmol of triethylamine to 300 mL of N,N-dimethylformamide, stir and react at 25°C for 18 h, distill under reduced pressure, wash the product with water and ethanol, and dry it to obtain a polyamide modifier.

[0036] (4) 9.8 kg of nylon resin and 0.2 kg of polyamide modifier were mixed and spun in a melt spinning machine at a spinning temperature of 260 °C. The mixture was then stretched in a hot stretching device at a stretching temperature of 120 °C and a stretching ratio of 4 to obtain modified nylon yarn.

[0037] Comparative Example 4: The difference between this comparative example and Example 1 is that ethylenediamine is used instead of 2,2'-oxybis(ethylamine) when preparing the polyamide modifier.

[0038] (1) Add 50 mmol of imidoyl chloride monomer, 54 mmol of ethylenediamine, and 110 mmol of triethylamine to 300 mL of N,N-dimethylformamide, stir and react at 25°C for 18 h, distill under reduced pressure, wash the product with water and ethanol, and dry it to obtain a polyamide modifier.

[0039] (2) 9.8 kg of nylon resin and 0.2 kg of polyamide modifier were mixed and spun in a melt spinning machine at a spinning temperature of 260 °C. The mixture was then stretched in a hot stretching device at a stretching temperature of 120 °C and a stretching ratio of 4 to obtain modified nylon yarn. Example 2

[0040] (1) Add 220 mL of glacial acetic acid, 78 mmol of trimellitic anhydride, and 30 mmol of 2,2'-oxybis(ethylamine) into a flask equipped with a reflux tube, introduce nitrogen, heat to 115 °C, stir and react for 18 h, cool and filter, wash the product with methanol, and then recrystallize from dichloromethane to obtain an imide carboxyl monomer as a light yellow solid with a yield of 8.49 g.

[0041] (2) Add 70 mL of thionyl chloride, 0.015 mL of N,N-dimethylformamide, and 50 mmol of imidocarboxyl monomer to a flask equipped with a condenser reflux tube, heat to 70 °C, stir and react for 8 h, distill under reduced pressure, and dry to obtain imidocarboxyl chloride monomer as a light yellow solid with a yield of 18.20 g.

[0042] (3) Add 50 mmol of imidoyl chloride monomer, 60 mmol of 2,2'-oxybis(ethylamine), and 130 mmol of triethylamine to 400 mL of N,N-dimethylformamide, stir and react at 20°C for 18 h, distill under reduced pressure, wash the product with water and ethanol, and dry it to obtain a polyamide modifier.

[0043] (4) 9.4 kg of nylon resin and 0.6 kg of polyamide modifier were mixed and spun in a melt spinning machine at a spinning temperature of 240 °C. The mixture was then stretched in a hot stretching device at a stretching temperature of 120 °C and a stretching ratio of 4 to obtain modified high-strength nylon yarn. Example 3

[0044] (1) Add 220 mL of glacial acetic acid, 66 mmol of trimellitic anhydride, and 30 mmol of 2,2'-oxybis(ethylamine) into a flask equipped with a reflux tube, introduce nitrogen, heat to 120 °C, stir and react for 12 h, cool and filter, wash the product with methanol, and then recrystallize from dichloromethane to obtain an imide carboxyl monomer as a light yellow solid with a yield of 8.91 g.

[0045] (2) Add 50 mL of thionyl chloride, 0.03 mL of N,N-dimethylformamide, and 50 mmol of imidocarboxyl monomer to a flask equipped with a condenser reflux tube, heat to 60 °C, stir and react for 8 h, distill under reduced pressure, and dry to obtain imidocarboxyl chloride monomer as a light yellow solid with a yield of 18.61 g.

[0046] (3) Add 50 mmol of imidoyl chloride monomer, 50 mmol of 2,2'-oxybis(ethylamine), and 100 mmol of triethylamine to 300 mL of N,N-dimethylformamide, stir and react at 40°C for 12 h, distill under reduced pressure, wash the product with water and ethanol, and dry it to obtain a polyamide modifier.

[0047] (4) 9 kg of nylon resin and 1 kg of polyamide modifier were mixed and spun in a melt spinning machine at a spinning temperature of 250 °C. The mixture was then stretched in a hot stretching device at a stretching temperature of 100 °C and a stretching ratio of 4 to obtain modified high-strength nylon yarn.

[0048] The tensile properties of nylon yarn are tested according to the method specified in GB / T 14337-2022.

[0049] 5 mg of nylon yarn was placed in a thermogravimetric analyzer and tested in a nitrogen atmosphere with a heating rate of 10°C / min and a test temperature of 25-700°C.

[0050]

[0051] After testing, the nylon yarn of comparative example 1 has low breaking strength and elongation at break, and the temperatures at which the mass loss is 5% and 50% are low, and its tensile properties and heat resistance are poor.

[0052] The nylon yarns of Examples 1-3 were modified with a polyamide modifier. The polyamide modifier contains a large number of flexible ether bonds in its molecular chain, which significantly toughens the nylon yarns and improves their elongation at break. The rigid imide ring structure also strengthens the nylon yarns and improves their breaking strength. As a result, the nylon yarns maintain high elongation at break and toughness while also exhibiting high breaking strength. Furthermore, the imide ring structure exhibits strong high-temperature resistance and is resistant to thermal decomposition, significantly improving the heat resistance of the nylon yarns and significantly raising their thermal decomposition temperature.

[0053] In comparative example 2, when preparing the polyamide modifier, 4,4-chloroformylphenyl ether is used instead of the imidoyl chloride monomer, resulting in the polyamide modifier not containing the rigid and high-temperature resistant imide ring structure. The breaking strength of the nylon yarn cannot have both good breaking strength and elongation at break, and the thermal decomposition temperature is low, and the heat resistance is poor.

[0054] In Comparative Example 3, when preparing the imide carboxyl monomer, ethylenediamine is used instead of 2,2'-oxybis(ethylamine). Ethylenediamine does not contain ether bonds, resulting in the polyamide modifier having fewer flexible ether bonds than in Example 1. The toughening effect is poor, and the elongation at break of the nylon yarn is low, and it is impossible to have both good breaking strength and elongation at break.

[0055] In the preparation of the polyamide modifier in Comparative Example 4, ethylenediamine was used instead of 2,2'-oxybis(ethylamine). The obtained polyamide modifier had fewer flexible ether bonds than that in Example 1, resulting in poor toughening effect. The elongation at break of the nylon yarn was low, and it was impossible to achieve both good breaking strength and elongation at break.

[0056] It should be noted that the embodiments described above are intended to illustrate the present invention only and are not intended to limit the present invention in any way. While the present invention has been described with reference to exemplary embodiments, it should be understood that the terms used herein are descriptive and explanatory rather than limiting. The present invention may be modified as specified within the scope of the claims and revised without departing from the scope and spirit of the present invention.

Claims

1. A modified high-strength nylon yarn, characterized in that: The modified high-strength nylon yarn comprises 90-98 parts of nylon resin and 2-10 parts of polyamide modifier in parts by weight; The preparation process of the polyamide modifier comprises: adding an imide chloride monomer, 2,2'-oxybis(ethylamine), and triethylamine in a ratio of 1 mol: (1-1.2) mol: (2-2.6) mol to N,N-dimethylformamide, stirring for reaction, performing reduced pressure distillation, washing with water and ethanol, and drying to obtain the polyamide modifier; The structural formula of the imidoyl chloride monomer is: ; The preparation process of the imidoyl chloride monomer is: (1) Add glacial acetic acid, trimellitic anhydride, and 2,2'-oxybis(ethylamine) into a flask equipped with a condenser reflux tube, introduce nitrogen, stir the reaction, cool, filter, and wash with methanol. The product is recrystallized in dichloromethane to obtain an imide carboxyl monomer; (2) Add thionyl chloride, N,N-dimethylformamide, and imidocarboxyl monomer to a flask equipped with a condenser reflux tube, stir for reaction, and then perform vacuum distillation and drying to obtain imidocarboxyl chloride monomer; The ratio of trimellitic anhydride and 2,2'-oxybis(ethylamine) in (1) is (2-2.6) mol:1 mol; The ratio of thionyl chloride, N,N-dimethylformamide and imide carboxyl monomer in (2) is (1-1.4) L: (0.3-0.6) mL: 1 mol.

2. The modified high-strength nylon yarn according to claim 1, characterized in that: In the preparation process of the polyamide modifier, the reaction is stirred at 20-40° C. for 12-18 hours.

3. The modified high-strength nylon yarn according to claim 1, characterized in that: The reaction (1) is carried out at 115-120°C for 12-18 hours.

4. The modified high-strength nylon yarn according to claim 1, characterized in that: The reaction in (2) is stirred at 60-75°C for 5-8 hours.

5. A process for preparing the modified high-strength nylon yarn according to any one of claims 1 to 4, characterized in that: The preparation process comprises the following steps: mixing nylon resin and polyamide modifier, spinning the mixture in a melt spinning machine, and then drawing the mixture in a hot drawing device to obtain modified high-strength nylon yarn.

6. The process for preparing the modified high-strength nylon yarn according to claim 5, characterized in that: The temperature during the spinning is 240-260°C.

7. The process for preparing the modified high-strength nylon yarn according to claim 5, characterized in that: The temperature during the drawing is 100-120°C.

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